This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. My research revolves around two separate areas of study. The first area aims to elucidate some of the extracellular and intracellular signals that influence the formation of new platelets. Specifically, my lab examines how signals promote the formation of long filamentous strands from platelet-precursor cells called megakaryocytes. These long strands, called proplatelets, are thought to be the site of platelet assembly and release. However, very little is known about what events are necessary for proplatelets to form. The second area examines the changes in a class of proteins called small GTPases in response to platelet binding to extracellular matrices, a critical event in platelet-mediated hemostasis and wound healing. These GTPases serve of molecular switches that control the movement of signals from outside of the platelet to within the platelet, and dictate physiological changes to the platelet after injury to the blood vessel.